Power transmission mechanism

Abstract

A power transmission system having a resilient buffer to prevent generation and transmission of vibrations between gears below a predetermined rotational speed. A plate is mounted for relative circular movement on a driven gear and contains buffer springs to damp vibrations until positive engagement results. A clutch mechanism surrounds the buffer disk and uses a rotating ramp surface with centrifugally actuated caged members to separate the clutch from the gear above a predetermined speed.

What is claimed is: 
     
       1. A system for power transmission of a vehicle comprising: an internal combustion engine;   a driving wheel of said vehicle connected to said engine;   a transmission mechanism including resilient buffer means and clutch means disposed in a juxtaposed manner relative to said buffer means; gear power transfer means connected between said engine and one end of said transmission mechanism;     a rotary member;   a shaft connected between the other end of said transmission mechanism and said rotary member, said gear power transfer means always connected between said engine and said transmission mechanism, and said shaft always connected between said power transmission mechanism and said rotary member, said transmission mechanism transmitting rotational force from said engine to said rotary member during rotation of said engine, wherein said clutch means drivingly engages said first gear power transfer means so as to transmit the rotational force at a low range of engine rotation and wherein said clutch means is disengaged from said first gear power transfer means at a predetermined range of engine rotation such that the rotational force is transmitted through said buffer means.   
     
     
       2. A system of claim 1, further comprising: a cylindrical member (13) fitted to said shaft (8), said cylindrical member securing therein said resilient buffer means, said gear power transfer means comprising a gear (10) rotatably mounted on said cylindrical member; and   coupling means (17) extending between said gear and said cylindrical member to perform integral rotation therebetween, said cylindrical member being formed with an arcuate slot (20) to allow idle movement of said coupling member therein, so that integral rotation between said gear and said cylindrical member is prevented during idle movement.   
     
     
       3. The system of claim 2, wherein said resilient buffer means comprises a series of buffer springs (11) disposed on said cylindrical member and oriented on a common circle. 
     
     
       4. The system of claim 3, wherein said cylindrical member comprises a sleeve portion (13a) mounted on said rotary shaft for integral rotation therewith, and a flange portion (13b) connected to said sleeve portion, said flange portion being formed with holes (14) oriented on a common circle to receive said buffer springs and formed with said slot (20) to allow insertion of said coupling means. 
     
     
       5. The system of claim 2, wherein said cluch means has one end frictionally engageable with a side wall of said gear in response to rotation range outside of said predetermined range, to thus render said resilient buffer means inactive. 
     
     
       6. The system of claim 5, wherein said clutch means comprises first and second members (22 21) mounted on said rotary shaft, said first member (22) being positioned on one side of said gear and being axially movable, and said second member (21) being positioned on the other side of said gear, an end face (22b') of said first member being frictionally engageable with said side wall of said gear; and first means (35) to resiliently bias said first member toward said gear, said first means to bias being positioned at one side of said first member; and centrifugal actuated means responsive to the rotation of said rotor shaft to move said first member away from said gear face to allow buffering action of said resilient buffer means against biasing force of said first means to bias. 
     
     
       7. The system of claim 5, wherein said centrifugally actuated means comprises a disk (30) mounted on said rotary shaft and within said first member and having a ramp surface (30a); and a series of caged members (31) movable radially outwardly on said ramp surface in response to centrifugal force provided by the rotation of said rotary shaft to urge said first member away from said gear against biasing force of said first means to bias, when the rotation of said rotary shaft is at said predetermined range. 
     
     
       8. The system of claim 7, further comprising a second disk (23) mounted on said rotary shaft and positioned within said first member and having a second ramp surface (23a) and a second series of caged members (24) movable radially outwardly on said second ramp surface in response to centrifugal force provided by the rotation of said rotary shaft. 
     
     
       9. The system of claim 7, further comprising second means (32) to bias for allowing said first member to be brought into engagement with said side face of said gear when the rotation of the rotary shaft exceeds a second predetermined range, the biasing force of said second means to bias being smaller than that of said first means to bias. 
     
     
       10. The system of claim 8, further comprising second means (32) to bias for allowing said first member to be brought into engagement with said side face of said gear when the rotation of the rotary shaft exceeds a second predetermined range, the biasing force of said second means to bias being smaller than that of said first means to bias.